package com.longge;

import java.util.HashSet;

public class IsUnique {
    public boolean isUnique(String astr) {
        HashSet<Character> set = new HashSet<>();
        for (int i = 0; i < astr.length(); i++) {
            set.add(astr.charAt(i));
        }
        return set.size() == astr.length();
    }
}
